From the instruction manual introduction:
Jupiter Mission 1999 is a dynamic interactive space fantasy epic adventure comprised of eleven separate game programs. With a mixture of role-playing and arcade-style action, Jupiter Mission 1999 provides you with an exciting and accurate simulation of a voyage to the Jupiter system in search of the source of intelligent radio transmissions. As the main character in the epic, your decisions determine the course of the action and the development of the game. The outcome will depend on your intelligence, dexterity, and perseverance.
As the only survivor aboard the USSN Space Beagle, you must somehow complete your mission. You will remain onboard at all times and interact with the game through scanners, space probes, and mobile robot probes. JUPITER MISSION 1999 is an adventure game; you mustfigureoutwhat must be done throughout the game. There will be no one there with the right answer for you; you must solve the problems on your own.